Table 1 Different definitions of an emergency department

"The worldwide definition... traditionally implies the rapid and appropriate care of victims of traumatic and medical emergencies"

Sikka and Margolis [14]

"An organized hospital facility for the provision of unscheduled outpatient services to patients whose conditions are considered to require immediate care"

American Hospital Association [18]

"A hospital facility for the provision of unscheduled outpatient services to patients whose conditions require immediate care and is staffed 24 hours a day. If an ED provided emergency services in different areas of the hospital, then all of these emergency service areas are [included]... Off-site EDs that are open less than 24 hours are included if staffed by the hospital's ED"

Burt and McCaig (The Center for Disease Control and Prevention) [19]

A facility that "is publicized to the public by name, posted signs, advertising or other means as a place that provides care for emergency medical conditions on an urgent basis without requiring a previously scheduled appointment," or "a department that is designated as an emergency department by state licensure" or "a department that, during the prior calendar year, provided at least one-third of all its outpatient visits for the treatment of medical conditions on an urgent basis without requiring a previously scheduled appointment... Labor and Delivery Departments and Urgent Care Centers are considered to meet the above criteria. This definition applies whether the department is on or off campus, as long as it is a department of the hospital or critical access facility"

The Emergency Medical Treatment and Active Labor Act [10]

"A hospital department consisting of staff, facilities, and resources to provide emergency medical care for large numbers of emergency patients"

New York State Public Health Law [20]

We provide state-of-the-art evaluation and treatment for patients with a full spectrum of emergency medical needs"

New-York Presbyterian Hospital, New York City [21]

"A place to go when you need to be seen by a doctor quickly 24/7. They take care of everything and everyone there"

Anonymous patient, St. Luke's Roosevelt Hospital, New York, New York.

"The place people go when they feel their medical problem is serious enough that they can't wait to be seen by their regular doctor. The ED is always open, and will care for any person's medical problem regardless of their ability to pay"

Anonymous patient, Massachusetts General Hospital, Boston, Massachusetts